Some reference material on abrupt climate change caused by
thermohaline circulation disruption follows.
http://earthobservatory.nasa.gov/Features/PolarParadox/
http://tinyurl.com/ldbh8v
"... sea ice transported into the Greenland Sea has the ability to
cap mixing of fresh and saline water by putting in a freshened
surface layer which acts like an inversion on the ocean. It keeps
some of the ocean water from rising up and exchanging its heat with
the atmosphere ..."
"Based on ideas generated by Richard Alley, Wallace Broeker, and
others, it is suggested that an extreme melt event might be capable
of capping off the North Atlantic thermohaline circulation. The
freshened upper surface waters would also increase sea ice formation.
If the condition persisted over a few years, climate feedbacks due to
increased albedo and increased ice cover would cause a major cooling
of the high northern latitudes, potentially creating the beginning of
a glacial epoch."
http://en.wikipedia.org/wiki/Thermohaline_circulation
"Large influxes of low density meltwater from Lake Agassiz and
deglaciation in North America are thought to have led to a disruption
of deep water formation and subsidence in the extreme North Atlantic
and caused the climate period in Europe known as the Younger Dryas."
http://en.wikipedia.org/wiki/Younger_Dryas
"The Younger Dryas saw a rapid return to glacial conditions in the
higher latitudes of the Northern Hemisphere between 12,900–11,500
years before present (BP)[5] in sharp contrast to the warming of the
preceding interstadial deglaciation. The transitions each occurred
over a period of a decade or so.[6] Thermally fractionated nitrogen
and argon isotope data from Greenland ice core GISP2 indicate that
the summit of Greenland was ~15°C colder during the Younger Dryas[6]
than today. In the UK, coleopteran (fossil beetle) evidence suggests
mean annual temperature dropped to approximately 5°C,[7] and
periglacial conditions prevailed in lowland areas, while icefields
and glaciers formed in upland areas.[8] Nothing of the size, extent,
or rapidity of this period of abrupt climate change has been
experienced since.[5]"
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
